Process for cleaning animal fibers to prepare same for subsequent use in textile operations



Patented May 23, 1950 UNITED. STATES PATENT ANIMAL FIBERS I TO PREPARE SAME FOR 'SUBSEQUENT use IN TEXTILE OPERATIONS Manuel Lam. Lowell, Mass.

No Drawing. ApplioationDece-mber 27, 1948, Serial No. 718,898

The present invention relates .to thetreatment of animal fibers. and. is more particularly con cerned with. the preparation and cleaning of raw animal fibersv tor subsequent use in the manufacture of various types of cloths and. felts. Whil the process of the invention isparticularly adapt.- ed to the preparation and cleaning of raw wool; it is not limited thereto butfinds application in the treatment of other animal fibers such as alpaca, mohaincamels hair and the like.

V Naturally, in this. old and very well. developed art, there have been numerous processes for cleaning raw wool and the like and preparing it for manufacturing operations. Presentv day methods usually involve a preliminary washing or scouring of the animal fibers in a solution of soap or alkali or with a mixture of both. After scouring, the fibers are either dried or they may be soaked in a solution of sulphuric acid of 1% to 15% concentration by weight. After removing the excess of the acid solution by either pressing or centrifuging, the treated fibers are then dried and baked at a temperature up to 250 F. in order to char theve'getable matter and redder it removable by mechanical 'means. The animal fibers at this stage are usually, although not necessarily, treated in an aqueous alkaline solution to neutralize any sulphuric acid that may be left in the fibers. Then the fibers, if necessary, may be treated with a paint removing solvent to remove any branding paint which may be left in the fibers. The depaihting solvent is then Washed outfwith alkaline or neutral soap. The fibers at this point may or may not'be soaked in a depitching solution and the depitc'hing solution subsequently washed out, if necessary.

The disadvantages inherent in the foregoing procedural steps are obvious and have been known and appreciated in this art for many years. In

the first place, there has always been, and there I still remains, the serious problemof disposing of the wash waters and in their disposition there has been created the nuisance of stream pollution and consequent creation of a definite health menace. Secondly, because of the tor/ageing drastic treatment, the fibers have been necessarily weakened, sometimesto a-serious extent, and heir ultimate weight is considerably less than it would have been had less. drastic methods beenavailable. .By far the, most harmful of these tratme s a those employing stron alkalies and hydrolyzed sulphuric acid. As used herein the term "hydrolyzed .is employed to indicate that the ions of the sulphuric acid solution have become dissociated into electrically charged ions.

stated. diffe ently. the term hydrolyzed? will be employed to indicate a degree of ioni ati While it is robably unnecessary here so to st e. t s bv ous ha the, very number of th pri r, art treatmen steps mil t es s riou ly ainst. sound eco omy of opera ion By t e pre en inventi n the foregoing and other disadvantages of the prior art are obviated to a great extentlhe problem of wash water di p sal obviated entirely, the animal fib rs are in n way w ak ned or reduc d in we gh n for reasons to be po nt d ou hereinaf r. t n w process represents an optimum in ec nomi op ation.

. The und rlying co cept o he present nv on involves a treatment of. animal fib rs with a in a h chlori aci s9 hydrochloric acid solution which is bs a a ly nhydrolyzed or nil-ionized. This. is acco p hed by forming am ture of a hyd och o ac solutioa, f s r n h to be defined a er, w th a ketone effective to suppress or inhibitso t speak. the hydrolysis or ionization of the hydrochloric a drso uti m By way o e planation the foll wn may be. not d: .As. is well known. a hydr chlorio cid s lution is ionized and, wh n an electric current is passed through such hydro h ricac d so ut on. he so ti i conduct the electric current, Now, if this, "same hydrochloric acid solution is mixed with a sufficient amount of a ketone, this ionization, and consequentability of the solution to conduct the curnt. s nhib t d e.

Generally, in accordance with the practice of the invention, the following procedural steps are obseryedi Wool, or other animal f bers, is soaked tion-ketone mixture, with or withoutagitation, ior from to minutes. ,lternatively, the fibers may be soaked in a mixture made up by dissolving dry hydrogen chloride in the keton'e. Then the excess solution may prmay not -be removed either pressing or centrifuging. At this point the fibers are heated gently to a'temp'erature of 205 F. in order to remove and recover the solvent contained in the fibers. The fibers are then baked at a ternperature up to 230 F. for aibout 10 to 30 minutes to char and render the vegetable matter brittle and removable by mechai ical :m'eans. Naturally, ef isi e he QQ eI Y F I Q hydme i employ and h fi she the tem th shorter the time necessary to destroy the vegetable matter, lt should 'bdnoted that while the fib s a in/ he ihy m 'imp b a i isnlutionrke tone mi ,y heigrease. fat an O e n din and on the fibers are dissblyed'through the solvent action of the ketone and the hydrochloric A acid is carried into the vegetable matter much more rapidly than when a water solution is employed. Damage to fibers is reduced to a minimum, since the soaking is accomplished in about one-fourth of the time ordinarily employed with water solution and the acid, because of its unionized condition, does not adversely afi'ect the animal fibers. Furthermore, while the grease is being dissolved, practically all the paint and tar present are removed by ketone solvent-action.

After baking and removal of the vegetable matter by mechanical means, as by crushing and dusting, the fibers are ready for use in the manufacture of felt or cloth. No neutralization of the hydrochloric acid is necessary because this acidis volatile and has been driven oif during the heating steps.

The following may be given as a specific example in thepractice of the present invention:

100 lbs. of wool or sheepskins, either green or tanned, are soaked in a solution made up of 36 lbs. of concentrated commercial hydrochloric acid (approximately 35% HCl) and 364 lbs. of methylethyl ketone. Alternatively, the solution may be made up by dissolving 12 lbs. of dry hydrogen chloride in 364 lbs. of methylethyl ketone. The wool or sheepskins are allowed to soak in this mixture, with or without agitation, for 30 minutes. One soaking usually is sufiicient, but if a larger amount of dirt is present, the fibers may be rinsed in a second solution prepared as above for about 15 minutes. soaked may or may not then be centrifuged to remove the excess solution, although this is not necessary since leaving excess solvent and acid in the wool or skins does no harm. In any event, they are then placed in an oven where gentle heat is first applied (about 205 F.) The temperature is then raised to 225 F. and held for about minutes. At the lower temperature the contained solvent is driven off and recovered, while at the higher temperature, the ve etable matter is charred and rendered removable. After crushing and dustin the fibers are ready for use without further processing.

, Ordinary concentrated hydrochloric acid of commerce contains about dissolved hydro en chloride gas. In the practice of the invention the ratio of such hydrochloric acid solution to the ketone may vary between 1% of the acid and 99% ketone to 12% of the acid to 88% of the ketone. In keeping with the foregoing explanation with respect to hydrol sis or ionization, it should be borne in mind that the water content of the hydrochloric acid so ution-ketone mix must be kept below a point where hvdrolvsis or ionization would take place. Since up to 12% of 35% hydrochloric acid may be used, and since the latter acid is approximately two-thirds water, it follows that the hydrochloric acid-ketone mixture shouldv not contain over about 8% water.

In the treatment step, methylethyl ketone is,

preferred, although it is to be understood that other ketones such as acetone. dibutyl ketone, and methyl acetone could be employed.

The ketone em loyed may be distilled after.-

settling out the dirt, and-the clean solvent is then ready for re-use, the grease contained in' the solvent bein usable as such or it may be refined.

into lanolin. At this point it should be mentioned that by prior methods, wool grease (crude; lanolin) is recovered to the extent of-2-5-50% of the total grease removed from the fibers. By the present method, 95-100% of the total grease is The wool or skins thus recovered. The dry sediment, which has a high nitrogenous and potash content, may be employed as such as a valuable fertilizer. It is particularly adapted for this purpose because it is absolutely free of sproutable weeds, seeds, and live worm and bug pests in their egg or developed stages.

What is claimed is:

1. In a process for cleaning animal fibers and preparing them for subsequent use in the manufacture of various types of cloths and felts, the step consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid and a ketone effective to inhibit ionization of the hydroabout 8% water.

2. In a process for cleaning animal fibers and preparing them for subsequent use in the manufacture of various type of cloths and felts, the step consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid and a ketone effective to inhibit ionization of the hydrochloric acid, the ratio of acid to ketone being between 1% acid to 99% ketone and 12% acid to 88% ketone, said mixture containing not over about 8% water.

3. In a process for cleaning animal fibers and preparing them for subsequent use in the manufacture of various types of cloths and felts, the step consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid and methylethyl ketone, said mixture containing not over about 8% water.

4. In a process for cleaning animal fibers and preparing them for subsequent use in the manufacture of various types of cloths and felts, the step consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid and acetone, said mixture containing not over about 8% water.

5. In a process for cleaning animal fibers and preparing them for subsequent usein the manufacture of various types of cloths and felts, the step consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid and dibutyl ketone, said mixture containing not over about 8% water.

6. In a process for cleaning animal fibers and preparing them for subsequent use in the manufacture of various types of cloths and felts, the steps consisting of subjecting said fibers to a mixture of concentrated hydrochloric acid, and

a ketone effective to inhibit ionization of the steps consisting of subjecting said fibers to a solution of dry hydrogen chloride in a ketone effective to inhibit ionization of the hydrochloric acid, removing excess mixture, heating the fibers to. drive 01? the ketone, recovering the ketone, and further heating to char the vegetable matter contained in and on the fibers, said solution containing not over about 8% water.

MANUEL LEVIN.

(References on following page) 5 6 REFERENCES CITED FOREIGN PATENTS The following references are of record in the Number Country Date me of this patent: 307,944 Great Britain Mar. 11, 1929 UNITED STATES PATENTS 6 OTHER. REFERENCES Number Na Date Claflin, "Phys. Chem. 01' the Carbonizing Proc- 549532 Rice et a1 Nov-12, 1895 ess," Amer. Dyest. Rep. xxx No. 20 (Sept. 26. 1,615,783 Bergmann et a1. Jan. 25, 1927 1932 pages 575.571 1,686,837 Pott Oct. 9, 1928 10 2,155,161 Fabian et a1 Apr. 18, 1939 2,393,712 Seymour et a1 J an. 29, 1946 

1. IN A PROCESS FOR CLEANING ANIMAL FIBERS AND PREPARING THEM FOR SUBSEQUENT USE IN THE MANUFACTURE OF VARIOUS TYPES OF CLOTHS AND FELTS, THE STEP CONSISTING OF SUBJECTING SAID FIBERS TO A MIXTURE OF CONCENTRATED HYDROCHLORIC ACID AND A KETONE EFFECTIVE TO INHIBIT IONIZATION OF THE HYDROCHLORIC ACID, SAID MIXTURE CONTAINING NOT OVER ABOUT 8% WATER. 